Fish Sulfa (Sulfamethoxazole 400mg / Trimethoprim 80mg) — 60 Tablets delivers a powerful dual-action antibiotic combination for ornamental and aquarium fish dealing with stubborn gram-positive and gram-negative bacterial infections. Each tablet contains a synergistic 960mg combination of two proven antibacterial agents — Sulfamethoxazole and Trimethoprim — working together through two separate and complementary mechanisms to deliver broader and more effective bacterial elimination than either ingredient could achieve alone.
This dual-action formula is what sets Fish Sulfa apart from single-ingredient fish antibiotics. Sulfamethoxazole disrupts bacterial folic acid synthesis — blocking the production of folate that bacteria need to grow. Trimethoprim then targets the next step in the same pathway — inhibiting dihydrofolate reductase to further block bacterial reproduction. This sequential two-step attack on bacterial metabolism makes Fish Sulfa highly effective against bacterial strains that may have developed resistance to single-mechanism antibiotics like penicillins or cephalosporins.
Each bottle contains 60 tablets — providing a full multi-course supply for ongoing ornamental fish care. Fish Sulfa tablets dissolve quickly in tank water for fast and even antibiotic distribution throughout your aquarium. Available at CalVetSupply without a vet prescription for ornamental and aquarium fish use only.
ACTIVE INGREDIENTS
Capsule Count: 60 Tablets per bottle
HOW MANY TREATMENTS DOES 60 TABLETS PROVIDE?
Based on 1 tablet per 10 gallons dosing guideline. Always follow product label directions.
WHAT DOES FISH SULFA TREAT?
Fish Sulfa (Sulfamethoxazole/Trimethoprim 960mg) is effective against the following bacterial conditions in ornamental freshwater and saltwater fish:
WHY FISH SULFA'S DUAL-ACTION FORMULA WORKS
Most fish antibiotics attack bacteria through a single mechanism. Fish Sulfa's combination formula hits two separate points in the same essential bacterial metabolic pathway — making it significantly harder for bacteria to develop resistance:
HOW TO USE FISH SULFA
Important: Always complete the full treatment course even if symptoms improve early. Stopping treatment prematurely increases the risk of antibiotic resistance.
WHEN TO USE FISH SULFA
Fish Sulfa is the right choice when your ornamental fish shows:
Fish Sulfa treats bacterial infections only — it is not effective against fungal or parasitic conditions.
PRECAUTIONS & SAFETY
FAQ
Q: What is Fish Sulfa used for? A: Fish Sulfa (Sulfamethoxazole 400mg / Trimethoprim 80mg) treats fin rot, tail rot, columnaris, bacterial gill disease, gram-positive and gram-negative bacterial infections, and bacterial septicemia in ornamental aquarium fish.
Q: What makes Fish Sulfa different from other fish antibiotics? A: Fish Sulfa combines two antibacterial agents — Sulfamethoxazole and Trimethoprim — that attack two separate steps in the same bacterial metabolic pathway. This dual-action mechanism delivers broader coverage and lower resistance risk than single-ingredient antibiotics like Fish Mox or Fish Flex.
Q: How many treatments does the 60-tablet bottle provide? A: For a 10-gallon hospital tank using 1 tablet per day the 60-tablet bottle provides up to 60 treatment days — enough for multiple complete 5-day treatment courses. See the treatment chart above for larger tank sizes.
Q: How quickly does Fish Sulfa work? A: Fish Sulfa typically begins showing results within 24–48 hours with significant improvement observed by the end of the 5-day treatment course. Recovery speed depends on infection severity and water conditions.
Q: Do I need a prescription to buy Fish Sulfa? A: No. Fish Sulfa is available at CalVetSupply without a vet prescription for ornamental aquarium fish use only.
Q: Is Fish Sulfa safe for live plants? A: Fish Sulfa is generally safe for live aquarium plants at recommended doses. Monitor sensitive plants closely during treatment and avoid exceeding recommended dosage.
Q: Can Fish Sulfa be used in saltwater tanks? A: Yes. Fish Sulfa is effective in both freshwater and saltwater aquariums. Always follow label dosage directions for correct treatment.
Q: How long does Fish Sulfa treatment take? A: Treat daily for up to 5 days. Always complete the full course even if symptoms improve early to prevent antibiotic resistance.
Q: Can I feed my fish during Fish Sulfa treatment? A: Yes. Feed your fish as normal during treatment but avoid overfeeding — excess food degrades water quality and adds stress during the treatment period.
Q: What if my fish shows no improvement after 5 days? A: Discontinue use and consult an aquatic veterinarian. Persistent symptoms may require a different antibiotic or a more specific diagnosis to identify whether the condition is bacterial, fungal, or parasitic.
